This invention relates to fluid control valves. In particular, this invention relates to an improved fluid control valve apparatus and method for the transfer of fluids in a safe and controlled manner.
The prior art is replete with valves designed to ensure the controlled transfer of fluids. Many specialized valves have been developed for various industries. Nonetheless, no single valve has been developed that is capable of operating safely throughout a wide range of operating pressures. Additionally, prior art valves are not easily adjustable so as to accommodate a range of operating pressures.
By way of example and not by limitation, the transfer of aviation gasoline and jet fuel poses several difficult problems. To begin with, the type of fuel contained in a tanker fuel delivery truck must be ascertained with certainty. A plane that runs on aviation gasoline will not run on jet fuel and vice versa. Additionally, these fuel transfers are difficult since the transfers are typically done from the tanker trucks to underground storage vessels at fuel farms with the only means of transfer being gravity flow. What is required in this situation, and many others, is a controllable valve capable of precise performance in low pressure environments. Further, a fluid control valve is required that is also easily adaptable for use in high-pressure environments as well. Hazardous locations with explosive atmospheres such as these raise many additional concerns such as the risks of providing electrical power to transfer devices.
Thus, there is the need in the art for providing an improved fluid control valve apparatus and method controllable for use in low and high-pressure environments, which is safe and easy to use and that does not increase the risks normally associated with the transfer of fluids.
Accordingly, the improved fluid control valve of the present invention includes a valve body with an inlet and an outlet. A sealing member is connected to the valve body and is conformed to seal the inlet and form a pressure chamber. A push rod is connected to the sealing member and a sleeve, encompassing the push rod, is provided. A piston, forming an equalization chamber, is connected to the sleeve and to the push rod so that when the piston moves in one direction the sealing member is moved in the opposite direction.
In a further aspect of the invention, a first port is provided in the pressure chamber operable between an open position and a closed position. A second port is provided in the equalization chamber and is connected to the first port when the first port is open. In another aspect of the invention, a third, bypass, port is connected to the second port when the first port is in the closed position for directing fluid leaking into the equalization chamber away from the equalization chamber.
In another aspect of the invention, a connecting arm, with a first end and a second end, is connected to the piston on the first end. A leverage generator is connected to the second end of the connecting arm and a pivotable push rod is connected to the leverage generator and to the push rod.
In a further aspect of the invention, a first spring encompasses the sleeve and urges the piston towards the inlet. A second spring encompasses the push rod and urges the sealing member toward the outlet so as to seal the inlet. In a another aspect of this invention, the connecting arm and leverage generator cooperate such that the leverage generator pivots to a position where the second spring urges the sealing member towards the inlet.
In yet another aspect of the invention, a sensor for testing the fluid prior to delivery is provided and the sensor includes a specific gravity meter and a sight glass.
In another preferred embodiment of the invention, in a system where fluid is transferred from one vessel to another, a method of controlling fluid flow includes the steps of forming a valve body with an inlet and an outlet. A sealing member is connected to the valve body and is conformed to seal the inlet and form a pressure chamber. A push rod is connected to the sealing member. The push rod is encompassed by a sleeve. A piston is connected to the sleeve, so as to form an equalization chamber behind the pressure chamber, and to the push rod so that when the piston moves in one direction the sealing member is moved in the opposite direction.
A first port is formed in the pressure chamber operable between an open position and a closed position. A second port is formed in the equalization chamber connected to the first port when the first port is open so that when fluid is introduced in the pressure chamber and the first port is opened fluid in the pressure chamber will be directed through the first and second port and fluid will fill the equalization chamber thereby equalizing the pressure between the pressure chamber and the equalization chamber. The fluid then forces the piston towards the outlet causing the sealing member to move away from the inlet and opening the valve. Next, a discharge line is connected to the inlet and a fill line is connected to the outlet. Finally, fluid is introduced into the valve and the first port is opened.
In a further aspect of the method of the invention, a connecting arm, with a first end and a second end, is attached to the piston at the first end. A leverage generator is connected to the second end of the connecting arm and a pivotable push rod is connected to the leverage generator and to the push rod.
In another aspect of the invention, a first spring is attached to the sleeve such that the first spring urges the piston towards the inlet and a second spring is attached to the push rod such that the second spring urges the sealing member toward the outlet so as to seal the outlet. In a further aspect of the invention, the connecting arm and the leverage generator are connected such that the leverage generator rotates to a xe2x80x9ccam overxe2x80x9d position where the second spring urges the sealing member towards the inlet.
In a further aspect of the invention, the spring tensions are adjusted for the first and second springs such that the valve opens and shuts at any desired fluid pressure. And, in yet a another aspect of the invention, a timer is added to the valve for delaying the closing of the valve for a predetermined time after fluid flow is stopped.